CN109891116B

CN109891116B - Damping valve for shock absorber

Info

Publication number: CN109891116B
Application number: CN201780067576.1A
Authority: CN
Inventors: A·艾希
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2016-11-04
Filing date: 2017-10-04
Publication date: 2021-09-28
Anticipated expiration: 2037-10-04
Also published as: US11098781B2; CN109891116A; DE102016221659B4; US20200063818A1; KR20190080910A; WO2018082852A1; DE102016221659A1

Abstract

Damping valve (1) comprising a damping valve body (3) having at least one through-channel (7) whose outlet cross-section (23) is at least partially covered by at least one valve disk (13), wherein the at least one valve disk is pretensioned by at least two star springs (31, 33, 35), wherein each star spring has a bearing ring (37, 39, 41) and a plurality of radial spring arms (45), wherein the bearing rings are stacked on one another in a mounted position, wherein the star springs are arranged in a congruent manner such that the spring arms of at least two adjacent star springs point in the same direction relative to the valve disk, and wherein the star spring group has a torsion stop element (53, 59, 61, 69, 71, 73) in an assembled position.

Description

Damping valve for shock absorber

Technical Field

The present invention relates to a damping valve for a shock absorber according to the preamble of claim 1.

Background

DE 761446B discloses a damping valve having a damping valve body with a through-passage whose outlet cross section is at least partially covered by a valve disk. The star spring causes the necessary closing force of the valve disk, which is supported on the support disk to limit the lifting movement of the valve disk. The star spring has a support ring with a plurality of spring arms extending radially outward from the support ring. The spring arms are not connected to each other except for the support ring, so that each spring arm can be deformed independently of the adjacent spring arm.

Between the spring arms, a free space extends, which forms in particular a flow path for further through-channels having an opposite flow direction. The free space has a larger cross section in the circumferential direction than the spring arms.

DE 2353402 a1 discloses a damping valve in which a star spring is likewise used in the embodiment according to fig. 4 and 5. The star springs with the basic design according to DE 761446B are arranged in opposite layers, i.e. the bearing rings are in contact, and the spring arms extend with their bearing rings facing each other.

In principle, the star spring offers the advantage that an asymmetrical closing force can be applied to the valve disk. Although in principle it is also possible to achieve a greater closing force, the life of the star spring is significantly reduced as a result.

Disclosure of Invention

The aim of the invention is to reduce the problem of life limitation in the case of higher loading of the star spring.

This object is achieved thereby: the star springs are stacked in the same direction, so that the spring arms of at least two adjacent star springs point in the same direction relative to the valve disk, and the star spring package has a rotation-blocking element in the assembled position.

The advantage of the invention is that, since instead of a single star spring, a plurality of individual weaker star springs are now used, they are significantly less critical in terms of life. However, in order to precisely concentrate the tension of the individual star springs and not to have the spring arms mounted without pretension or with reduced pretension, a torsion-blocking element is used which leads to a stacked arrangement of the spring arms. The stack arrangement must only be maintained during transport from the material silo until the loading of the completed damper valve. In the case of a completely assembled damper valve, the friction force keeps the spring arms in a stacked arrangement even if the torsion stop element is no longer active.

In one embodiment, the rotation-blocking element is formed by at least one weld. In principle, spring steel may be more difficult to weld than structural steel, however the load on the stack during assembly is very small.

It has proven to be particularly advantageous if the weld is embodied as a resistance weld. The resistance welding portion can realize a short tact time and a simple structure.

In order to also be able to weld a plurality of star springs to one another precisely, the star springs have at least one access opening, which is at least partially covered by an adjacent star spring with a carrier section. Therefore, two adjacent spider springs are always welded to each other. If more than two star springs are used in the stack, the star springs then have a plurality of access openings which are arranged in a defined angular position with respect to the spring arms. In this case, the carrier section can be brought into register with the plurality of access openings very easily by means of the pivoted mounting position, and thus it is also ensured that the welding tool can approach both carrier sections in the middle of the stack and only then weld them to one another in a targeted manner.

Alternatively, the weld can be embodied as a laser weld, which is very advantageous in particular in terms of the introduction of heat into the star spring.

With regard to the fastening in the low-stress region of the star spring, the torsion-blocking element outside the spring arm establishes a connection with the bearing ring.

Additionally, the bearing ring can have at least one radial projection for arranging the rotation-blocking element. The radial protrusion does not actually change the spring characteristics of the spider spring.

For example, in the event that a suitable welding technique cannot be provided, the rotation-blocking element can also be formed by a securing bolt which projects beyond the bearing ring.

In principle, the rotation-blocking element can also be formed by a fixing sleeve, which forms an interference connection with the bearing ring, for example.

It is therefore possible for the fixing sleeve to act on the support ring on the inside. Even if the fixing sleeve projects slightly axially beyond the stack of bearing rings, there is still no functional disadvantage, since the installation space for the stack provides sufficient free space for this purpose.

Alternatively, the fixing sleeve can also act on the support ring on the outside and have a recess for accommodating the spring arm. For example, an annular base can be provided, which has an axial projection which then engages into the free space between the spring arms of the star spring.

Depending on the size and material properties of the star spring, it can also be provided that the bearing rings are connected to one another by means of a snap connection. The snap-in engagement need not have a locking head. The radial pressing-in on a small cross section is sufficient to fix the spider springs to one another for the assembly process.

In principle, it is also possible to adhesively bond the support rings to one another. This variant requires particularly low expenditure.

Drawings

The invention is further elucidated with the aid of the following description of the figures. Wherein:

FIG. 1 shows a damping valve in a sectional illustration;

FIG. 2 shows a top view of the spider spring;

figures 3 and 4 show details of the spider spring set;

FIG. 5 shows a spider spring pack with a dead bolt;

FIGS. 6 and 7 show a spider spring pack with a fixed sleeve;

FIG. 8 shows a spider spring pack having a bite joint;

FIG. 9 shows a spider spring pack with laser welds;

fig. 10 shows a star spring package with an adhesive connection.

Detailed Description

Fig. 1 shows a damping valve 1 in the form of a piston valve. In principle, however, the invention is not limited to this form of construction. The damping valve 1 comprises a damping valve body 3 which has at least one through-channel 7 at the piston rod 5 which can connect a working chamber 9 remote from the piston rod with a working chamber 11 on the piston rod side. The outlet cross section of the at least one through-channel 7 is at least partially covered by a valve disk 13. For this purpose, the plurality of through-channels 7 open into an annular groove 15, which is delimited by a valve seat inner face 17, a valve seat outer face 19 and also forms an outlet cross section.

On a sub-circle radially inward with respect to the inner face 17 of the valve seat are further through-passages 21 for the flow from the working chamber 11 on the piston rod side to the working chamber 9 remote from the piston rod. The through-channel 21 likewise opens into an annular groove 23 on the bottom side of the damping valve body 3 and is covered by a second valve disk 25, which is prestressed in the closing direction by a helical spring 27. In principle, other spring types can also be used.

The valve disk 13 on the upper side of the damping valve body 3 has a through-opening 29 which opens into the through-passage 21. The star springs 31, 33, 35 are prestressed in the closing direction of the valve disk 13, and they abut with their inner bearing rings 37, 39, 41 against a bearing disk 43. All the support rings 37, 39, 41 are stacked and pressed between the damping valve body 3 with the valve disk 13 and the support disk 43.

Fig. 2 shows a plan view of the star springs 31, 33, 35. Each

spider spring

31, 33, 35 has a

bearing ring

37, 39, 41 from which a plurality of spring arms 45 extend radially. In fig. 2, the spring arms 45 extend radially outward. The invention also contemplates an outer support ring and radially inwardly directed spring arms.

Within the limits of manufacturing tolerances, all

spring arms

45, 47, 49 are stacked with maximum overlap, wherein, as shown in fig. 1, all

spring arms

45, 47, 49 of at least two adjacent star springs point in the same direction relative to valve disk 13. Additionally, with reference to fig. 3, the

respective spring arms

45, 47, 49 of the laminated star springs 31, 33, 35 can be clearly seen therein.

The star spring arrangement according to fig. 1 to 3 has a rotation-blocking element in the assembled position, i.e. corresponding to fig. 3, which causes the angular orientation of all

spring arms

45, 47, 49 to also coincide. It should be avoided that the star spring is mounted in a torsional manner with respect to the adjacent star spring and thus its spring arms engage in the free space 51 between two spring arms of the adjacent star spring.

In the embodiment according to fig. 2 and 3, the rotation-blocking element is formed by a weld 53 in the resistance-welded embodiment. Between two adjacent spring arms and thus beyond the spring arms, each bearing

ring

37, 39, 41 has a radial projection 55 at its outer diameter for the arrangement of a rotation-blocking element 53. In this case, one of the radial projections has an access 57, which is at least partially closed by the adjacent star spring 33 with its bearing ring 39.

Fig. 2 shows a

star spring

31, 33, 35 with six radial projections 55. If star springs differing in material size are used, then the star springs 31, 35 on the surface side can each be provided with an access 57, and the middle star spring 33 is embodied without an access. Thus, two adjacent star springs can be welded to one another without problems, wherein the access facilitates the contact between the electrode and the central star spring 33 (see fig. 4)

If more than three star springs of the same type are welded, it is proposed here that a respective radial projection 55 of the star springs is embodied without an access 57 and the other projections 55 are embodied with accesses 57. When the star springs are stacked in groups, two adjacent star springs are aligned with their inlets 57 in accordance with one another. Therefore, the projections 55 without the access ports 57 coincide in the axial direction, and can thus be easily welded.

The subsequent star spring pair is assembled in an offset manner to one spring arm, but with the same orientation of the inlet as the first star spring pair. The welding tool can thus be guided by the existing access openings of the star springs above and below it to the star spring pair in the middle thereof, in order to weld them at their radial projection without access opening.

In fig. 5, all radial projections 55 have an access 57, through which a securing bolt 59 penetrates the bearing rings 37, 39, 41 as a rotation-blocking element. However, in this variant, a radial projection may not necessarily be necessary. In principle, the radial projections 55 serve to provide a radial cross section which unloads the bearing ring. In the corresponding support ring cross-section, the pronounced radial projection 55 can be dispensed with.

It has been found that the respective torsion stop element 57 can exert a sufficiently large holding force in order to hold the star spring package together during the assembly process.

Fig. 6 shows a section through the

star spring package

31, 33, 35 with a fixing sleeve 61 as a rotation-blocking element, which acts on the inside on the bearing rings 37, 39, 41 and forms an interference fit therewith. When assembled, the individual star springs 31, 33, 35 are aligned with one another in the circumferential direction and then introduced into the fixing sleeve 61. The fixing sleeve may protrude beyond the spider spring pack. A small free space for accommodating the projecting sleeve volume can be provided in the support disk.

Fig. 7 shows that the fixing sleeve 61 can also act on the support rings 37, 39, 41 on the outside in such a way that it has a recess 63 for accommodating the

spring arms

45, 47, 49. The fixing sleeve 61 has a base 65, as well as the planar extension of the support rings 37, 39, 41. Starting from this base, retaining webs 67 extend, which engage between the

spring arms

45, 47, 49 and with their inner walls abut the edges of the bearing rings 37, 39, 41.

Fig. 8 shows a further variant in which the bearing rings are connected to one another by a rotation-blocking element in the form of a snap connection 69. The snap-in connection does not have to be embodied such that a complete locking head is present. The press fit between the regions of the bearing rings 37, 39, 41 that engage into one another is sufficient to achieve the required holding force.

In a further embodiment according to fig. 9, the rotation-blocking element is formed by a laser weld 71, which is preferably implemented at the outer edge region of the bearing rings 37, 39, 41, since access for welding tools is particularly simple here. The laser weld 71 exhibits a particularly low thermal load and can therefore also be used particularly well in the case of very thin walls of the spider springs 31, 33, 35.

In principle, it is also possible according to fig. 10 to bond the bearing rings 37, 39, 41 of the star springs 31, 33, 35 to one another by means of an adhesive layer 73 between the star springs 31, 33, 35, so that the adhesive layer forms a rotation-blocking element. Due to the low requirements, simple adhesive techniques can also be used, since, as already mentioned, the durability of the adhesive connection is not necessary.

List of reference numerals

1 damping valve

3 damping valve body

5 piston rod

7 through channel

9 working chamber far away from piston rod

11 working chamber on the piston rod side

13 valve disk

15 annular groove

17 inner face of valve seat

19 outside the valve seat

21 through passage

23 annular groove

25 valve disk

27 helical spring

29 cross section through

31 control spring

33 control spring

35 control spring

37 support ring

39 supporting ring

41 supporting ring

43 support disc

45 spring arm

47 spring arm

49 spring arm

51 free space

53 weld

55 radial projection

57 connecting port

59 fixing bolt

61 fixed sleeve

63 recess

65 bottom

67 holding tab

69 bite joint

71 laser welding part

73 adhesive layer

Claims

1. A damper valve (1) comprising a damper valve body (3) having at least one through-channel (7) whose outlet cross-section (23) is at least partially covered by at least one valve disk (13), wherein the at least one valve disk (13) is prestressed by at least two star springs (31, 33, 35), wherein each star spring (31, 33, 35) has a support ring (37, 39, 41) and a plurality of radial spring arms (45), wherein the support rings (37, 39, 41) are stacked on one another in a mounted position, characterized in that the star springs (31, 33, 35) are stacked in the same direction, such that the spring arms (45) of at least two adjacent star springs point in the same direction relative to the valve disk (13), and in that the star spring group has a torsion stop element (53, 53) in the mounted position, 59. 61, 69, 71, 73), the rotation-blocking element (53, 59, 61, 69, 71, 73) being connected to the bearing ring (37, 39, 41) outside the spring arms (45), the rotation-blocking element holding each two adjacent star springs together before the complete damper valve is installed, so that a star spring group is formed.

2. The damper valve according to claim 1, characterized in that the torsion stop element is formed by at least one weld (53).

3. The damper valve according to claim 2, wherein the welded portion (53) is a resistance welded portion.

4. Damping valve according to claim 1, characterized in that the star spring (31, 33, 35) has at least one access (57) which is at least partially covered by an adjacent star spring (31, 33, 35) with a support ring (37, 39, 41).

5. The damper valve according to claim 2, characterized in that the weld (53) is a laser weld (71).

6. The damper valve according to claim 4, characterized in that the bearing ring (37, 39, 41) has at least one radial projection (55) for arranging the torsion stop element (53).

7. The damper valve according to claim 1, characterized in that the torsion stop element is formed by a securing bolt (59) which is clamped over the bearing ring (37, 39, 41).

8. The damper valve according to claim 1, characterized in that the torsion stop element is formed by a fixing sleeve (61).

9. The damper valve according to claim 8, characterized in that the fixing sleeve (61) acts on the support ring (37, 39, 41) on the inside.

10. The damping valve according to claim 8, characterized in that the fixing sleeve (61) acts on the support ring (37, 39, 41) on the outside and has a recess (63) for accommodating the spring arm (45).

11. The damper valve according to claim 1, characterized in that the support rings (37, 39, 41) are connected to one another by means of a snap-in joint (69).

12. Damping valve according to claim 1, characterized in that the support rings (37, 39, 41) are glued to each other.